This patch improves functions my_xxx_to_str() using the idea
introduced in this change in MySQL-8.0:

  commit 8d10f2fff6bbdea7f436b868ebb5fd811defc68a
  Author: Knut Anders Hatlen <knut.hatlen@oracle.com>
  Date:   Thu Oct 10 13:55:07 2019 +0200
    Bug#30472888: IMPROVE THE PERFORMANCE OF INTEGER HANDLING IN THE TEXT PROTOCOL

The new way prints 2 digits at a time and demonstrates a very impressing query time reduce:
10% to 38%, depending on the exact data type and the number of fractional digits:

  SELECT BENCHMARK(10*1000*1000,CONCAT(TIME'10:20:30'));
  SELECT BENCHMARK(10*1000*1000,CONCAT(TIME'10:20:30.123456'));
  SELECT BENCHMARK(10*1000*1000,CONCAT(DATE'2001-01-01'));
  SELECT BENCHMARK(10*1000*1000,CONCAT(TIMESTAMP'2001-01-01 10:20:30'));
  SELECT BENCHMARK(10*1000*1000,CONCAT(TIMESTAMP'2001-01-01 10:20:30.123456'));

See MDEV for details on the benchmark results.

GCC before version 5 would fail to emit the CPUID instruction
when targeting IA-32 in -fPIC mode. Therefore, we must add the
CPUID instruction to the HAVE_CLMUL_INSTRUCTION check.

This means that the PCLMUL accelerated crc32() function will
not be available on i686 executables that are compiled with
GCC 4. The limitation does not impact AMD64 builds or non-PIC
x86 builds, or other compilers (clang, or GCC 5 or newer).

MDEV-22641 in commit dec3f8ca
refactored a SIMD implementation of CRC-32 for the ISO 3309 polynomial
that uses the IA-32/AMD64 carry-less multiplication (pclmul)
instructions. The code was previously only available in Mariabackup;
it was changed to be a general replacement of the zlib crc32().

There exist AMD64 systems where CMAKE_SYSTEM_PROCESSOR matches
the pattern i[36]86 but not x86_64 or amd64. This would cause a
link failure, because mysys/checksum.c would basically assume that
the compiler support for instruction is always available on GCC-compatible
compilers on AMD64.

Furthermore, we were unnecessarily disabling the SIMD acceleration
for 32-bit executables.

Note: Until MDEV-22749 has been implemented, the PCLMUL instruction
will not be used on Microsoft Windows.

Closes: #1660

If statement still contains changes it must be committed
before actual transaction is committed.

This assertion was found using randgen and happens only on
applier. No repeatable test case found.

When duplicates are removed from a table using a hash, if the record is a duplicate it is marked
as deleted. The handler API check if the record is deleted and send an error flag HA_ERR_RECORD_DELETED.
When we scan over the table if the thread is not killed then we skip the
records marked as HA_ERR_RECORD_DELETED.

The issue here is when a query is aborted by a user (this is happening when the LIMIT for ROWS EXAMINED
is exceeded), the scan over the table does not skip the records for which HA_ERR_RECORD_DELETED is sent.
It just returns an error flag HA_ERR_ABORTED_BY_USER.
This error flag is not checked at the upper level and hence we hit the assert.
If the query is aborted by the user we should just skip reading rows and return
control to the upper levels of execution.

Field::make_new_field() resets invisible property (needed for "CREATE
.. SELECT" f.ex.).  Recover invisible property in
Delayed_insert::get_local_table() (unireg_check works by the same
principle).

This bug was originally repeated on 10.4 after defining a UNIQUE KEY
on a TEXT column, which is implemented by MDEV-371 by creating the
index on a hidden virtual column.

While row_vers_vc_matches_cluster() is executing in a purge thread
to find out if an index entry may be removed in a secondary index
that comprises a virtual column, another purge thread may process
the undo log record that this check is interested in, and write
a null BLOB pointer in that record. This would trip the assertion.

To prevent this from occurring, we must propagate the 'missing BLOB'
error up the call stack.

row_upd_ext_fetch(): Return NULL when the error occurs.

row_upd_index_replace_new_col_val(): Return whether the previous
version was built successfully.

row_upd_index_replace_new_col_vals_index_pos(): Check the error
result. Yes, we would intentionally crash on this error if it
occurs outside the purge thread.

row_upd_index_replace_new_col_vals(): Check for the error condition,
and simplify the logic.

trx_undo_prev_version_build(): Check for the error condition.

mtr_t::init(): Correct the debug assertion that was added in
commit c8936686 (MDEV-22970).
When the original failure scenario involves the system tablespace,
we could have m_user_space==nullptr. Let us compare m_user_space_id
instead.

Revert change to MDL and set SST donor thread as a system thread.
Joiner thread was already a system thread.

Sys_var_bit::session_save_default() ignored reverse_semantics property.

Key buffer needs to contain max field widths i.e. add MAX_FIELD_WIDTH.

MDEV-22055: Assertion `active() == false' failed in wsrep::transaction::start_transaction upon ROLLBACK AND CHAIN

The optional AND CHAIN clause is a convenience for initiating a new
transaction as soon as the old transaction terminates. Therefore,
do not start new transaction if it is already started
at wsrep_start_transaction.

fix the following type mrr scan
(select 0,`id`,`node` from `auto_test_remote`.`tbl_a` where (`id` <> 0) order by `id`)union all(select 1,`id`,`node` from `auto_test_remote`.`tbl_a` where (`id` <> 0) order by `id`) order by `id`

MDEV-23562 Assertion `time_type == MYSQL_TIMESTAMP_DATETIME' failed upon SELECT from versioned table

The code in vers_select_conds_t::init_from_sysvar() assumed that
the value of the system_versioning_asof is DATETIME.
But it also could be DATE after a query like this:
  SET system_versioning_asof = DATE(NOW());

Fixing Sys_var_vers_asof::update() to convert the value
of the assignment source to DATETIME if it returned DATE.

Now vers_select_conds_t::init_from_sysvar() always gets a DATETIME value.

Problem:

Queries like this showed performance degratation in 10.4 over 10.3:

  SELECT temporal_literal FROM t1;
  SELECT temporal_literal + 1 FROM t1;
  SELECT COUNT(*) FROM t1 WHERE temporal_column = temporal_literal;
  SELECT COUNT(*) FROM t1 WHERE temporal_column = string_literal;

Fix:

Replacing the universal member "MYSQL_TIME cached_time" in
Item_temporal_literal to data type specific containers:
- Date in Item_date_literal
- Time in Item_time_literal
- Datetime in Item_datetime_literal

This restores the performance, and make it even better in some cases.
See benchmark results in MDEV.

Also, this change makes futher separations of Date, Time, Datetime
from each other, which will make it possible not to derive them from
a too heavy (40 bytes) MYSQL_TIME, and replace them to smaller data
type specific containers.

fix the following type mrr scan
(select 0,`id`,`node` from `auto_test_remote`.`tbl_a` where (`id` <> 0) order by `id`)union all(select 1,`id`,`node` from `auto_test_remote`.`tbl_a` where (`id` <> 0) order by `id`) order by `id`

Match 10.5 path changes in:
 * b2feb030
 * aaaf005c
 * bb847777

Implementing methods:
- Field::val_time_packed()
- Field::val_datetime_packed()
- Item_field::val_datetime_packed(THD *thd);
- Item_field::val_time_packed(THD *thd);
to give a faster access to temporal packed longlong representation of a Field,
which is used in temporal Arg_comparator's to DATE, TIME, DATETIME data types.

The same idea is used in MySQL-5.6+.

This improves performance.

Problem:

When calculatung MIN() and MAX() in a query with GROUP BY, like this:

  SELECT MIN(time_expr), MAX(time_expr) FROM t1 GROUP BY i;

the code in Item_sum_min_max::update_field() erroneosly used
string format comparison, therefore '100:20:30' was considered as
smaller than '10:20:30'.

Fix:

1. Implementing low level "native" related methods in class Time:
     Time::Time(const Native &native)           - convert native to Time
     Time::to_native(Native *to, uint decimals) - convert Time to native

   The "native" binary representation for TIME is equal to
   the binary data format of Field_timef, which is used to
   store TIME when mysql56_temporal_format is ON (default).

2. Implementing Type_handler_time_common "native" related methods:

  Type_handler_time_common::cmp_native()
  Type_handler_time_common::Item_val_native_with_conversion()
  Type_handler_time_common::Item_val_native_with_conversion_result()
  Type_handler_time_common::Item_param_val_native()

3. Implementing missing "native representation" related methods
   in Field_time and Field_timef:

  Field_time::store_native()
  Field_time::val_native()
  Field_timef::store_native()
  Field_timef::val_native()

4. Implementing missing "native" related methods in all Items
   that can have the TIME data type:

  Item_timefunc::val_native()
  Item_name_const::val_native()
  Item_time_literal::val_native()
  Item_cache_time::val_native()
  Item_handled_func::val_native()

5. Marking Type_handler_time_common as "native ready".
   So now Item_sum_min_max::update_field() calculates
   values using min_max_update_native_field(),
   which uses native binary representation rather than string representation.

   Before this change, only the TIMESTAMP data type used native
   representation to calculate MIN() and MAX().

Benchmarks (see more details in MDEV):

  This change not only fixes the wrong result, but also
  makes a "SELECT .. MAX.. GROUP BY .." query faster:

  # TIME(0)
  CREATE TABLE t1 (id INT, time_col TIME) ENGINE=HEAP;
  INSERT INTO t1 VALUES (1,'10:10:10'); -- repeat this 1m times
  SELECT id, MAX(time_col) FROM t1 GROUP BY id;

  MySQL80: 0.159 sec
  10.3:    0.108 sec
  10.4:    0.094 sec (fixed)

  # TIME(6):
  CREATE TABLE t1 (id INT, time_col TIME(6)) ENGINE=HEAP;
  INSERT INTO t1 VALUES (1,'10:10:10.999999'); -- repeat this 1m times
  SELECT id, MAX(time_col) FROM t1 GROUP BY id;

  My80: 0.154
  10.3: 0.135
  10.4: 0.093 (fixed)

Raspberry Pi 4 supports crc32 but doesn't support pmull (MDEV-23030).

The PR #1645 offers a solution to fix this issue. But it does not consider
the condition that the target platform does support crc32 but not support PMULL.

In this condition, it should leverage the Arm64 crc32 instruction (__crc32c) and
just only skip parallel computation (pmull/vmull) rather than skip all hardware
crc32 instruction of computation.

The PR also removes unnecessary CRC32_ZERO branch in 'crc32c_aarch64' for MariaDB,
formats the indent and coding style.

Change-Id: I76371a6bd767b4985600e8cca10983d71b7e9459
Signed-off-by: Yuqi Gu <yuqi.gu@arm.com>

In trx_free() we used to declare the entire trx_t unaccessible
and then declare that some data members are accessible.
This involves a race condition with other threads that may concurrently
access the data members that must remain accessible.
One type of error is "AddressSanitizer: unknown-crash", whose
exact cause we have not determined.

Another type of error (reported in MDEV-23472) is "use-after-poison",
where the reported shadow bytes would in fact be 00, indicating that
the memory was no longer poisoned. The poison-access-unpoison race
condition was confirmed by "rr replay".

We eliminate the race condition by invoking MEM_NOACCESS on each
individual data member of trx_t before freeing the memory to the pool.
The memory would not be unpoisoned until the pool is freed
or the memory is being reused for another allocation.

trx_t::free(): Replaces trx_free().

trx_t::active_commit_ordered: Changed to bool, so that MEM_NOACCESS
can be invoked. Removed some accessor functions.

Pool: Remove all MEM_ instrumentation.

TrxFactory: Move the MEM_ instrumentation from Pool.

TrxFactory::debug(): Removed. Moved to trx_t::free(). Because
the memory was already marked unaccessible in trx_t::free(), the
Factory::debug() call in Pool::putl() would be unable to access it.

trx_allocate_for_background(): Replaces trx_create_low().

trx_t::free(): Perform all consistency checks while avoiding
duplication, and declare most data members unaccessible.